Omaha police said the assault happened near 21st and Burt streets around 3 p.m. Friday.

Officers said the victim, identified as Aquilee Muse, was walking with several teenagers when they were confronted by two teens. Police said Muse was involved in a physical altercation with the two teens and received a head injury.

Muse was taken to the Nebraska Medical Center in very critical condition. His family told KETV NewsWatch 7 he was pronounced brain dead Tuesday morning and was taken off the ventilator Tuesday afternoon.

Muse was pronounced dead at 3:30 p.m.

"Keke was a wonderful, loving and funny kid. He could put a smile on anyone's face. We always said that he should have his own comedy show. He loved to eat cereal, but more importantly, he loved his family and friends. He was deeply involved with church and carried his Bible in his backpack. We love him, and will miss his big, bright smile every day. During this difficult time, we ask you to please respect our family's privacy as we continue to grieve," said the family of Aquilee "Keke" Muse.

The Douglas County Attorney's Office confirms Markell Vaughn, 16, and Trevaun Ammons, 16, will each be charged as adults with first-degree assault.

The county attorney's office said it's actively involved in this investigation.